Circuit board guide and support apparatus having improved fastenings for rigid assembly

ABSTRACT

An improved circuit board guide includes an element which has a longitudinal board-receiving groove in the front surface and which has spaced, cylindrical protrusions on the back surface, each protrusion having a central bore therein which receives a mounting pin that is attached to a mounting bar. The cylindrical protrusions are received in recesses about the mounting pins to form a rigid structure that supports a circuit board along opposite longitudinal edges.

United States Patent [191 Muldoon, Jr.

[ 51 May 29, 1973 [54] CIRCUIT BOARD GUIDE AND SUPPORT APPARATUS HAVINGIMPROVED FASTENINGS FOR RIGID ASSEMBLY [76] Inventor; Edward M. Muldoon,Jr., 3817 Mistral Drive, Huntington Beach, Calif. 92649 [22] Filed: Oct.4, 1971 [21] Appl. No.: 186,251

[52] US. Cl. ..3l7/10l DH, 317/100 [51] Int. Cl. ..II05k [58] Field ofSearch ..3l7/99, 100, 101 DH,

[56] References Cited UNITED STATES PATENTS 1/1966 Calebro ..3l7/10012/1971 Wenz ..317/10O 3,212,568 10/1965 Frawley ..3l7/l00 FOREIGNPATENTS OR APPLICATIONS 1,361,752 4/1964 France ..317/101 PH PrimaryExaminer-Herman J. Hohauser Assistant Examiner-Gerald P. TolinAttorney-A. C. Smith [57] ABSTRACT An improved circuit board guideincludes an element which has a longitudinal board-receiving groove inthe front surface and which has spaced, cylindrical protrusions on theback surface, each protrusion having a central bore therein whichreceives a mounting pin that is attached to a mounting bar. Thecylindrical protrusions are received in recesses about the mounting pinsto form a rigid structure that supports a circuit board along oppositelongitudinal edges.

2 Claims, 2 Drawing Figures I CIRCUIT BOARD GUIDE AND SUPPORT APPARATUSHAVING IMPROVED F ASTENINGS FOR RIGID ASSEMBLY BACKGROUND OF THEINVENTION Certain known circuit board supports or guides suitable forstacking a large number of circuit boards in a small housing, or cardcage," commonly rely on spring wire forms or sheet metal pieces to formthe desired supports and guides for the circuit boards. One disadvantageencountered in guides of this type is that numerous fastenings to thesurrounding housing are required to assure adequate rigidity andalignment of the guide grooves.

SUMMARY OF THE INVENTION The improved circuit board support and guideassembly includes two principal elements which may be assembled inmultiple arrays to provide a versatile mounting structure for supportingcircuit boards in close, spaced relationship. The guide element includesa longitudinal groove disposed in one surface to receive the edge of acircuit board and also includes mounting pylons or protrusions disposedin spaced relationship on the opposite surface. These protrusionsinclude a central bore and are arranged to fit snugly into recessesmating mounting bars. The mounting bars may include a plurality ofspaced recesses, each including a pin which protrudes from the base ofthe recess to engage the central bore in the corresponding protrusion ofa guide element. Lateral slots on the guide elements which engage themounting bars reduce rotational movement about the protrusions andthereby enhance the shear stability of the structure.

DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view ofthe guide element and mounting bars; and

FIG. 2 is a perspective view of the guide element showing theconstructional details of the pylons and slots on the rear surface ofthe guide element.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIG. 1, thereis shown a guide element 9 which includes a longitudinal groove 11 thatmay communicate at least with the entrance end 13 to form anedge-receiving guide for a circuit board 15. The guide element 9 mayinclude at a location along the groove 11, say, near the entrance end 13a lateral recess 17 in the groove which cooperates with a boardejectingor locking mechanism that forms no part of the present invention.

The guide element carries a plurality of spaced, cylindrical protrusionsor pylons 21 on the reverse face, as shown in FIG. 2, which are arrangedto fit into mating recesses 22 in the mounting bars 23. These pylons arespaced at selected intervals along the length of the guide element 9 andare, in part,.the means for attaching the guide element 9 to themounting bars 23. These pylons 21 are press fitted into the matingrecesses 22 of slightly smaller diameter in the mounting bars 23.Additionally, a spring pin 24 may be carried either by the guide element9 for engaging the aperture 25 in the base of the recess 22 in themounting bar 23, or preferably, the spring pin 24 may be carried by themounting bar 23 to engage the central bore 26 in the pylon 21 of theguide element 9. This latter configuration is preferred for improvedthermal conduction between pins and mounting bars that aids in reducingthermal softening of plastic materials typically used in the guideelements 9. In either configuration, the spring pin 24 may be a splitdrive pin that is snugly fitted into the bar 23 or element 9 whichcarries it, as the case may be.

Referring now to FIG. 2, the reverse side of the guide element 9includes a recessed slot 27 having a width dimension 28 that isapproximately equal to the width 29 of the corresponding mounting bar23. The mating engagement of these lateral recessed slots 27 with thecorresponding mounting bars 23 provides shear stability which aids inmaintaining orthogonal orientation of the guide elements 9 and mountingbars 23. In addition, the mounting bars 23 may include tapped holes 31in the ends thereof to facilitate attachment to an end plate or frame36. Thus, in a typical application of the present invention, a pair ofguide elements 9 are arranged to receive opposite edges of a circuitboard and are pressfittedly attached to sets of mounting bars 23 on eachside of the circuit board. For short circuit boards, correspondinglyshort guide elements 9 having only two pylons 21 may be used whereas forlonger boards, longer guide elements 9 having three or more pylons 21may be used. The set of mounting bars adjacent one edge of a circuitboard and the set of mounting bars adjacent the opposite edge of thecircuit board are attached to end plates or frames 36 which may alsosupport an edge-receiving circuit board connector 35 at the distal end33 of, and in line with, the longitudinal grooves 11 in the associatedpair of guide elements 9. Adjacent pairs of guide elements 9 may belaterally spaced any selected distance as established by the spacing 37between adjacent recesses 22 in the sets of mounting bars 23. In thepreferred embodiment of the invention, the guide elements may be castfrom such materials as glass-reinforced Nylon or Delrin and the mountingbars may be formed of aluminum or plastic, or the like, to provide ahigh degree of rigidity as well as slippery guide grooves to facilitateeasy insertion and withdrawal of circuit boards. Of course, the pairs ofguide elements 9 and the associated mounting bars 23 therefor may beoriented to permit either horizontal or vertical sliding movement of thecircuit boards supported thereby.

I claim:

1. Circuit board support apparatus comprising:

a guide element having a longitudinally-oriented groove in one facethereof which is disposed to receive an edge of a circuit board therein;

said guide element including a plurality of mounting means on a secondface thereof which is opposite said one face; and for each of saidmounting means a mounting bar disposed in substantially perpendicularrelationship to the groove in said guide element and being attached tosaid guide element by a corresponding one of said mounting means; saidmounting means includes a recessed, lateral slot in said second face ofthe guide element, said slot having a width substantially equal to thewidth of said mounting bar and being in snug engagement therewith toprevent relative rotation of said intersecting 65 bar and element aboutthe mounting means therebetween; said mounting means also includes aprotuberance of selected external dimension on said second face of saidelement, and said bar includes in mating engagement with said pin, withsaid protuberance disposed within said mating recess.

2. Circuit board support apparatus as in claim 1 wherein said pin isresiliently biased in the radial direction resiliently engaging saidmounting bar and said protuberance for snugly retaining said guideelement and mounting bar against relative movement in a direction alongthe length of said pin.

1. Circuit board support apparatus comprising: a guide element having alongitudinally-oriented groove in one face thereof which is disposed toreceive an edge of a circuit board therein; said guide element includinga plurality of mounting means on a second face thereof which is oppositesaid one face; and for each of said mounting means a mounting bardisposed in substantially perpendicular relationship to the groove insaid guide element and being attached to said guide element by acorresponding one of said mounting means; said mounting means includes arecessed, lateral slot in said second face of the guide element, saidslot having a width substantially equal to the width of said mountingbar and being in snug engagement therewith to prevent relative rotationof said intersecting bar and element about the mounting meanstherebetween; said mounting means also includes a protuberance ofselected external dimension on said second face of said element, andsaid bar includes a mating recess which has an inner dimensionsubstantially equal to said external dimension of said protuberance onthe guide element and which snugly engages said protuberance in saidrecess; and said mounting means includes a pin centrally disposed withinsaid recess in said mounting bar, and said protuberance on said secondface of said guide element includes a centrally-disposed bore therein inmating engagement with said pin, with said protuberance disposed withinsaid mating recess.
 2. Circuit board support apparatus as in claim 1wherein said pin is resiliently biased in the radial directionresiliently engaging said mounting bar and said protuberance for snuglyretaining said guide element and mounting bar against relative movementin a direction along the length of said pin.